hi, is it possible to force a selected crypto for SRTP as i cant seem to find a way to force a crypto to the user such that is phone uses that for media, secondly i see zoiper sends the below in SDP a=crypto:5 AES_256_CM_HMAC_SHA1_80 inline:854nJNIKSyhr0sJs+Ol+Qv2eSqC2gnydK8iVHUAXb4Xx7oW8iMM2jVi7R9xV6A== a=crypto:6 AES_256_CM_HMAC_SHA1_32 inline:854nJNIKSyhr0sJs+Ol+Qv2eSqC2gnydK8iVHUAXb4Xx7oW8iMM2jVi7R9xV6A== a=crypto:3 AES_192_CM_HMAC_SHA1_80 inline:854nJNIKSyhr0sJs+Ol+Qv2eSqC2gnydK8iVHUAXb4Xx7oW8iMM= a=crypto:4 AES_192_CM_HMAC_SHA1_32 inline:854nJNIKSyhr0sJs+Ol+Qv2eSqC2gnydK8iVHUAXb4Xx7oW8iMM= a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:854nJNIKSyhr0sJs+Ol+Qv2eSqC2gnydK8iVHUAX a=crypto:2 AES_CM_128_HMAC_SHA1_32 inline:854nJNIKSyhr0sJs+Ol+Qv2eSqC2gnydK8iVHUAX where as FS always uses the below only switch_core_media.c:1484 Found suite AES_CM_128_HMAC_SHA1_80 and also i noticed FS and zoiper have some variations in crypto names such as switch_core_media.c:1479 looking for crypto suite [AES_CM_192_HMAC_SHA1_32] in [4 AES_192_CM_HMAC_SHA1_32 and this never matches and never used at all (notice the placement of CM_192 in FS whereas zoiper has 192_CM) -- Regards, Bipin ------------------------------------------------------------------------